1. Field of the Invention
Embodiments of the invention described herein pertain to the field of valves. More particularly, embodiments of the invention relate to check valves. Historically, check valves have used clackers or poppets within a body through which the liquid will flow to effect closure of the valve.
2. Description of the Related Art
Both the shape and location of such a clacker or poppet previously used has hitherto meant that there is potentially significant turbulence within the vicinity of such devices when they are in an open position, and any such turbulence will cause potential vibration and rotational relative movement.
Techniques which have hitherto been tried include adding a stem to the clacker or poppet which is located and held within a spider within the body where the spider provides a central aperture through which the stem of the clacker or poppet might be retained.
Attempts have been made to stop rotational movement by having the stem have a non-circular cross sectional shape and this shape matching a similarly shaped aperture through the center of the spider.
Unfortunately, over time, such a combination is very vulnerable to serious failure.
Such a problem is especially of concern when the check valve is at a discharge end of an electric submersible pump such as those used in deep well pumping operations.
Two major problems occur when a check valve fails in this situation, namely when the discharge outlet gets blocked off, the pressure created in the pump is not registered by a pressure switch at a head of the well, so that the pump then will run continuously until burn out or fusion occurs.
A second problem occurs when the valve clacker does not return properly.
This can be as a result of mechanical malfunction or it can be as a result of impurities or sediment within the liquid, such as water, that is being pumped.
Leakage resulting from this will cause the pressure switch to restart the pump because of the pressure drop.
Such a restart often engages while the electric motor is running in reverse at high speed, brought on by a turbine action of the quickly returning water through the pump.
A restart at this point will result in burn out because an overload will drop out too late.
Burn out costs of these pumps is very high indeed.
Further, because such submersible pumps might be anything from 100 to 1000 meters underground, it can take many days to retrieve the pump and check valve in order to perform a replacement or repair.
While this is one illustration of a problem, check valves generally have high failure rates in other applications such as industrial applications and are currently a major cause of production loss.
Failure typically will cause a shut down of a production process while it is replaced.
The problem addressed by this invention then is to propose a check valve that, at the least, provides for an improved reliability in use, or at the least, provides the public with a useful alternative.